Nancucheo Ivan, Johnson D Barrie
Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Lientur 1457, Concepción 4080871, Chile.
School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 4UF, UK.
Microorganisms. 2020 Jul 2;8(7):990. doi: 10.3390/microorganisms8070990.
Reactive pyritic mine tailings can be populated by chemolithotrophic prokaryotes that enhance the solubilities of many metals, though iron-reducing heterotrophic microorganisms can inhibit the environmental risk posed by tailings by promoting processes that are the reverse of those carried out by pyrite-oxidising autotrophic bacteria. A strain (IT2) of , a bacterium not previously identified as being associated with acidic mine wastes, was isolated from pyritic mine tailings and partially characterized. Strain IT2 was able to reduce ferric iron under anaerobic conditions, but was not found to catalyse the oxidation of ferrous iron or elemental (zero-valent) sulfur, and was an obligate heterotrophic. It metabolized monosaccharides and required small amounts of yeast extract for growth. Isolate IT2 is a mesophilic bacterium, with a temperature growth optimum of 30 °C and is moderately acidophilic, growing optimally at pH 4.0 and between pH 2.7 and 5.0. The isolate tolerated elevated concentrations of many transition metals, and was able to grow in the cell-free spent medium of the acidophilic autotroph , supporting the hypothesis that it can proliferate in acidic mine tailings. Its potential role in mitigating the production of acidic, metal-rich drainage waters from mine wastes is discussed.
活性黄铁矿尾矿中可能存在化能自养原核生物，这些生物会提高许多金属的溶解度，不过铁还原异养微生物可以通过促进与黄铁矿氧化自养细菌相反的过程来抑制尾矿带来的环境风险。从黄铁矿尾矿中分离出了一株细菌（IT2），该细菌此前未被鉴定为与酸性矿山废弃物有关，并对其进行了部分特性分析。菌株IT2能够在厌氧条件下还原三价铁，但未发现其催化二价铁或元素态（零价）硫的氧化，且为专性异养菌。它能代谢单糖，生长需要少量酵母提取物。分离株IT2是嗜温菌，最适生长温度为30℃，且中度嗜酸，在pH 4.0以及pH 2.7至5.0之间生长最佳。该分离株能耐受多种过渡金属的高浓度，并且能够在嗜酸自养菌的无细胞废培养基中生长，这支持了它能在酸性矿山尾矿中增殖的假说。文中讨论了其在减轻矿山废弃物产生酸性富金属排水方面的潜在作用。
